Circuit interrupter with improved molded insulating housing formed with vent passage means

ABSTRACT

A circuit interrupter comprises a molded insulating housing molded to form improved vent passage means for venting arc gases from the housing.

United States Patent Yorgin et al. [4 1 Dec. 26, 1972 54 CIRCUITINTERRUPTER WITH [581 mu of Search ..2o0/144 R, 168 R IMPROVED MOLDEDINSULATING HOUSING FORMED WITH VENT [56] References Cited PASSAGE MEANSi UNITED STATES PATENTS [72] Inventors: Nick Yorg n, Ambridge; John G.

3,489,872 l/l970 Casey ..200/l44 R Beaver Falls bah 3,564,176 2/1971Fechant... ..200/144 R [73] Assignee: Westinghouse Electric Corporation,3,422,235 1/1969 Camp ..200/ 144 R X Pittsburgh, Pa. 3,349,204 l0/l967Fair ..200/l44 R X Filed? June 1971 Primary Examiner-H. 0. Jones [21]Appl, No.1 153,198 Attorney-A. T. Stratt0n et al.

Related US. Application Data 57 ABSTRACT Division Of 114 197, l- Acircuit interrupter comprises a molded insulating housing molded to formimproved vent passage means 1 for venting arc gases from the housing.[52] U.S. Cl. ..200/l68 R, 200/144 R [51] Int. Cl. ..H01h 9/30, HOlh33/76 4-Claim s, 8 Drawing Figures H J 101 T PATENT'ED DEC 26 I9723,707,612

sum 1 0F 3 FL. L

PATENTED DEC 2 s 1972 sum 3 or 3 FIG. 5

CIRCUIT INTERRUPTER WITH IMPROVED MOLDED INSULATINGHOUSING FORMED WITHVENT PASSAGE MEANS CROSS REFERENCE TO RELATED APPLICATION Thisapplication is a division of the application of Nick Yorgin et al. Ser.No. ll,452 filed Feb..l6, 1970 now US. Pat. No. 3,632,939.

BACKGROUND OF THE INVENTION l. Field of The Invention Circuitinterrupters of the type comprising a molded insulating housing and acircuit interruptor mechanism supported in the molded insulatinghousing.

2. Description of The Prior Art his old in the circuit interruptor artto provide a molded insulating housing for the interruptor with cavitiesat one end for receiving the terminals of the interruptor and with wirescreens, or insulating barriers having openings therein, supported onthe insulating housing for venting gases from the housing into the areaof the cavities. This invention is an improvement over the prior art inthat the insulating housing is molded to form vent passages that leadinto the terminal cavities with the vent passages being directed towardthe sidewalls of the terminal cavities to make it more difficult for anelongated wire or other foreign member to be moved into the housingthrough the vent passages.

SUMMARY. OF THE INVENTION An improved circuit interruptor comprises amolded insulating housing and a circuit interrupter mechanism supportedin the insulating housing. The insulating housing comprises moldedprojection means extending from an end wall to form a plurality ofcavities at an end of the interrupter for receiving. solderless terminalconnectors. The molded projection means forms generally planar spacedparallel surfaces that extend from the end wall along parallel planeswhich parallel surfaces serve as side walls of the cavities. The endwall of the insulating housing has a thickness dimension. The end wallis molded to form a plurality of vent passages through the thicknessthereof for each pole unit of the interrupter. At each pole unit thevent passages extend from the inner surface of the end wall to the othersurface of the end wall diverging toward the side walls of theassociated cavity to thereby provide vent passages that do not readilyreceive elongated wires or other foreign members that could be movedinto the housing through the vent passages.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a top plan view ofa circuitinterrupter constructed in accordance with the principles of thisinvention; i

FIG. 2 is a side sectional view taken generally along the line II-II ofFIG. 1;

FIG. 3 is a partial sectional view taken generally BRIEF DESCRIPTION OFTHE PREFERRED EMBODIMENTS Referring to the drawings, there is shown, inFIGS. 1 and 2, a multi-pole molded-case or insulating housing typecircuit interrupter 3. The circuit interrupter 3 is a circuit breaker ofthe type that is more specifically described in the copendingapplication of Nick Yorgin et al. US. Pat. No. 3,460,075 issued Aug. 5,1969. Thus, only a brief description of the circuit interrupter isprovided herein. The circuit interrupter comprises an insulating housing5 and a circuit interrupter mechanism 7 supported in the housing 5. Thehousing 5 comprises a molded insulating base 9 and a molded insulatedcover 11 secured to the base 9 to enclose the circuit interruptermechanism that is mounted on the base 9. The insulating housing 5 willbe hereinafter more specifically described. 7 v

The circuit interrupter mechanism 7 comprises an operating mechanism 13,a latch mechanism 15 and a trip device 17'.

A stationary contact 19, a movable contact 2l and an arc-extinguishingunit 23 are provided for each pole of the circuit interrupter. Themovable contact 21 is mounted on a movable contact arm 25 that isconnected to a switch arm 26 that is secured to an insulating common tiebar 27. The tie bar 27 is supported for pivotal movement abouttheelongated axis thereof. A toggle, comprising a toggle link 29 and atoggle link 31, is pivotally connected at one end thereof to the movableswitch arm' 26 of the center pole unit and at the other end thereof to alatched trip member 33 that is pivotally supported on a pin 35. that ismounted between a pair of supporting plates 37. An operating tensionspring 39 is connected at one end thereof to the knee pivot 41 of thetoggle and at the other end thereof to the bight portion of an invertedgenerally U-shaped operating member 43. A handle 45 extends from thelever 43 through an opening in the front of the housing cover 11 topermit manual operation of the interrupter. The releasable trip member33 is latched at one end thereof by means of a roller latch member 47that is in turn latched by an elongated insulated trip bar 49 that ismounted for pivotal movement about the elongated axis thereof. Theoperating lever 43 is an inverted U- shaped lever that is mounted at theends of the legs thereof in U-shaped notches in the supporting plates37.

The circuit interrupter is manually operated by operation of the handle45 from the open position seen in FIG. 2 in a clockwise direction to theclosed position during which movement the line of action of the spring39 is moved to the right to erect the toggle 29, 31 to pivot the movableswitch arm 26 in a clockwise direction to the closed position.

The interrupter is manually opened by reverse movement of the handle 45in a counterclockwise direction to the open position during whichmovement the line of action of the spring 39 is moved to the left tocollapse the toggle 29, 31 to thereby move the switch arm 26 of thecenter pole unit to the open position seen in FIG. 2.

Since all three of the switch arms 26 for the three pole units of thethree-pole circuit interrupter are fixed to the common tie bar 27,operation of the center-pole tripping operation in the same manner aswas hereinbe- I fore described following a time delay thermal trippingswitch arm 26 simultaneously operates all three of the ble conductor 61,a conducting member 63,-to a terminal connector 65.

Upon the occurrence of an overload above a first predetermined value,the bimetal 51 becomes heated and flexes to the right (FIG. 2) whereuponthe screw 53 engages the trip bar 49 to rotate the trip bar 49 in aoperation.

The insulating base 9 (FIGS. 2 and 5) is a molded insulating membermolded with integral barriers 87 that cooperate with barriers'89 (FIGS.2, 6 and 7),'that are molded integral with the insulating cover 11, toseparate the housing 5 into three adjacent pole-unit compartments. Thebarriers 87, 89 are formed to provide parts that overlap in order toprevent the passage of gases between adjacent pole units. The base andcover, however, engage each other at a generally planar engagement asshown by the line 90 (FIGS. 2

counterclockwise direction whereupon the trip bar 49 releases the latch47. Upon release of the latch 47, the

spring 39, operating through the toggle 29, 31, pivots the trip member33 in a clockwise direction with the latch 47 moving in a clockwisedirection about its pivot 71. This movement changes the line of actionof the spring 39 whereupon the spring collapses the toggle 29, 31 tomove the movable switch arms 26 to the open position. During thetripping operation, the spring 39 moves the handle 45 to a positionintermediate the ON and OFF positions to provide a visual indicationthat the interrupter has tripped. Following a tripping operation, theinterrupter is reset by movement of the handle 45 in a counterclockwisedirection to a position slightly past the full OFF position. During thismovement, a projection 73 on the operating member 43 engages a shoulderon the trip member 33 to rotate the trip member 33 in a counterclockwisedirection during which movement the trip member 33 engages the latch 47to move the latch to the latching position, and a spring 77 moves thetrip. bar 49 to the latching position so that upon release of the handle45 the interrupter will be latched in the reset position seen in FIG. 2.Thereafter, the circuit interrupter can be manually operated in the samemanner as was hereinbefore described.

The circuit interrupter is magnetically tripped by operation of anelectromagnet that comprises a stationary magnetic member 81 and amovable magnetic armature 83 that is supported for pivotal movement bymeans of a pair of pivot arm supports 85. The current in the bimetal 51energizes the magnetic members 81, 83. Upon the occurrence of the severeoverload above a second predetermined value the armature 83 is attractedto the magnetic member 81 whereupon a part of the armature above thepivot support 85 thereof engages the trip bar 49 to rotate the trip bar49 in a counterclockwise direction to effect an instantaneous magnetictripping operation. A shunt conductor 86 on the armature 83 is utilizedto shunt current through the stationary magnetic member 81 to theconductor 63 to thereby shunt current past the bimetal upon theoccurrence of a magnetic tripping operation to protect the bimetalagainst excessive heating. The circuit interruptcr is reset following aninstantaneous magnetic and 4). As can be understood with reference toFIG. 2, there is 5 single operating mechanism 13 and single latchmechanism 17 in the center pole-unit compartment. The circuit in eachpole-unit is the same as that hereinbefore described with regard to thecenter poleunit, and there is a separate trip device 17 in each poleunit for operating the common trip bar 49 to trip the interrupter uponthe occurrence of an overload in any of the pole units. The insulatingcover 11 islformed with four openings 91 the'rethrough which align withtapped openings 93 in the insulating base 9 to receive four screws 95(FIG. 3) which serve to secure thecover 9 to the base 11. The insulatingbase 9 is formed with four openings 97 therethrough which align withfour openings 99 in the insulating cover 11 for receiving mounting boltsthat extend through the openings 97, 99 in the base and cover to securethe circuit interrupter 3 to a panel-at the installation. It isnecessary to insulate the mounting bolts from the internal live parts ofthe circuit-interrupter at the area where the cover 11 engages the base9. For example, when there is a circuit interruption, pressure generatedby the arcs can blow the cover and base slightly apart and the ionizedgases could cause a flashover from one of the poles to ground through amounting bolt that would be grounded at the installation. In order toadequately insulate the mounting bolts from internal live parts of thecircuit interrupter, the cover is molded with four insulating tubeportions 101 that are molded integral, with the cover, which tubeportions 101 nest within larger diameter opening portions 103 of theopenings 97 in the insulating base 9. The tube portions 101, nestingwithin the openings 103 of the base 9, extend through the plane of thegenerally planar engagement 90 between the base and cover to insulatethe mounting bolts from the internal live parts of the circuitinterrupter at the area where the insulating cover 11 engages theinsulating base 9.

As can be seen in FIG. 5, the insulating base 9 is molded with slotmeans 105 therein at each pole unit compartment at one end of the base9. The insulating cover is molded with slot means 107 therein at eachpole unit compartment, which slot means 107 aligns with the associatedslot means 105 of the base 9. During assembly of the circuitinterrupter, an insulating member 113 (FIG. 2) is positioned in theassociated slot means 105, 107 of each pole unit to close off endwallopenings in the insulating housing 5 at the arcextinguishing end of theinsulating housing 5. The base 9 is formed with slot means 117 thereinat each pole unit compartment thereof at the opposite end of the base 9.During assembly of the circuit interrupter, an insulating member 1 19(FIG. 2) is positioned in the slot means 117 before the cover 11 ismounted on the base. The top of the barriers 119 engage the bottomsurface of the cover end wall 123 when the cover is mounted on the base.As can be seen in FIG. 6, the insulating cover 11 is molded to provideand end wall part 123 at the one end of the housing with projections 125extending from the end wall 123 to cooperate with similar projections126 on the base 9 to provide three cavities 127 for the three terminalconnectors 65 at the one end of the interrupter. The projections 125,126 insulate the adjacent externally accessible terminal connectors 65from each other. As can be seen in FIG. 6, the end wall portion 123 ofthe cover 11 comprises an internal generally planar wall surface 129 andan external generally planar wall surface 131 at opposite sides of thethickness of the end wall portion 123. The projections 125 provide sidewall surfaces 133 at each cavity 127 which side wall surfaces 133 aregenerally parallel to each other and generally normal to the wallsurfaces 129, 131 of the end wall portion 123. The insulating cover 11is molded with two vent passages 137 at each pole unit thereof whichvent passages 137 diverge from the internal wall surface 129 through thethickness of the end wall portion 123 to the external wall surface 131in directions toward the side walls 133.

The ventpassages 137 in each pole unit vent arc gases out of theassociated pole unit. As can be seen and understood with reference toFIGS. 6 and 8, with the vent passages 137 diverging outward toward thecavity sidewall surfaces 133, a wire, for example, cannot easily bemoved from the external end of the housing into the internal compartmentof the housing through the vent passages.

By molding the vent passages and insulating tubes integral with thehousing, additional parts are eliminated,

inventory control is facilitated and time is saved during assemblythereby providing a cost saving in the manufacture of the circuitinterrupter. Moreover, there is a more reliable fitting of parts andreliability control is enhanced since there is less chance for humanerror during assembly of the circuit interrupter.

We claim as out invention:

1. A circuit interrupter comprising a molded insulating housing, acircuit-interrupter mechanism supported in said insulating housing, saidcircuit-interrupter mechanism comprising a pair of cooperable contactsoperable to open and close an electric circuit, said insulating housingcomprising a molded generally planar end wall at one end thereof andmolded projection means extending from said end wall to form a cavity atsaid one end, said molded projection means comprising generally planarspaced generally parallelsurfaces that extend from said end wall alonggenerally parallel planes that are generally normal to the plane of saidend wall which generally parallel'surfaces serve as cavity side wallmeans providing side walls of said cavity, said end wall having athickness dimension, and said end wall being molded to form a ventpassage through the thickness thereof which vent passage extends fromthe inner surface of said end wall to the outer surface of said end walltoward one of said side walls of said cavi- 2. A circuit interrupteraccording to claim 1, and said end wall being molded to form a pluralityof vent passages throu h the thickness thereof which vent passages extenfrom the inner surface of said end wall to the outer surface of said endwall toward said side wall means.

' 3. A circuit interrupter according to claim 2, and said vent passagescomprising a pair of vent passages through the thickness of said endwall which vent passages diverge from the inner surface of said end wallto the outer surface of said end wall toward said side walls of saidcavity.

4. A circuit interrupter according to claim 3, said insulating housingcomprising a back base housing part with said circuit-interruptermechanism supported thereon and a front cover housing part engaging saidbase housing part along a generally plane engagement between the backand the front of said insulating housing, and said pair of vent passagesbeing formed in said front cover housing part.

1. A circuit interrupter comprising a molded insulating housing, acircuit-interrupter mechanism supported in said insulating housing, saidcircuit-interrupter mechanism comprising a pair of cooperable contactsoperable to open and close an electric circuit, said insulating housingcomprising a molded generally planar end wall at one end thereof andmolded projection means extending from said end wall to form a cavity atsaid one end, said molded projection means comprising generally planarspaced generally parallel surfaces that extend from said end wall alonggenerally parallel planes that are generally normal to the plane of saidend wall which generally parallel surfaces serve as cavity side wallmeans providing side walls of said cavity, said end wall having athickness dimension, and said end wall being molded to form a ventpassage through the thickness thereof which vent passage extends fromthe inner surface of said end wall to the outer surface of said end walltoward one of said side walls of said cavity.
 2. A circuit interrupteraccording to claim 1, and said end wall being molded to form a pluralityof vent passages through the thickness thereof which vent passagesextend from the inner surface of said end wall to the outer surface ofsaid end wall toward said side wall means.
 3. A circuit interrupteraccording to claim 2, and said vent passages comprising a pair of ventpassages through the thickness of said end wall which vent passagesdiverge from the inner surface of said end wall to the outer surface ofsaid end wall toward said side walls of said cavity.
 4. A circuitinterrupter according to claim 3, said insulating housing comprising aback base housing part with said circuit-interrupter mechanism supportedthereon and a front cover housing part engaging said base housing partalong a generally plane engagement between the back and the front ofsaid insulating housing, and said pair of vent passages being formed insaid front cover housing part.